You just need a central tool to manage your subscriptions without all the dark patterns, where you can be sure if you terminate the subscription you 100% won't be billed again.
Also, pay as you go business models are great, but more work for app developers, so there'd need to be a good tool to make that easier.
This is why I like to pay via Apple App Store.
This is the crux of the matter. The laws are too weak. If the law said that that in addition to a refund there was a mandatory $100 compensatory payment due for every payment taken improperly (eg. every payment taken while unsubscription using the same method didn't work) then you'd have a few activist consumers waiting five years, recording the evidence and then demanding $6000. The problem would disappear overnight.
Of course you can take it to a court, wasting countless hours of time and risking tens of thousands in legal fees if you lose.
That's a huge exaggeration. For example in the UK (not in the EU now I know, but roughly the same and I know the system better) you're looking at risking under £200. The loser will pay the fees. If you're certain that you're owed compensation under the law then there's little risk to take.
Source: https://www.moneysavingexpert.com/reclaim/small-claims-court...
It doesn't matter to any single subscriber if two different countries happen to be in sync or not.
So... a bank?
The US's inability to forbid companies from stealing people's money is a pile of bullshit that makes the lives of everybody all over the world harder.
(Or maybe, that's a good opportunity for competing with them.)
But, of course, they don't interact directly with the US banks.